Cheika, now the Argentina coach, gave Petaia his debut Test jersey as a teenager in the 2019 Rugby World Cup.
The prodigious talent rewarded Cheika with an excellent performance in a beaten side, impressing at outside centre in the quarter final loss to England in Japan.
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The world seemed Petaia’s oyster but injuries and uncertainty over his best position have since slowed his progress in both Super Rugby and the international arena.
Tom Banks was Dave Rennie’s preferred fullback last year but the Brumbies star has left the door ajar by signing to play his club rugby in Japan next season.
Rennie has made it clear that he will favour Australian-committed players when it comes to tight selection calls.
“Banks is the incumbent – he hasn’t really ever arrived in that position,” Cheika said on Nine’s Sports Sunday.
“(Andrew) Kellaway’s a bit of a new kid on the block. I’m a big Jordan Petaia fan.
“At 15 he gives you something a bit different. Great in the air and if he can build his kicking game, he’s got X-factor as well, he can deliver something from the back.”
Cheika was asked directly if he thought Petaia was ready to play fullback at Test level.
“He never will be if he doesn’t get a chance. If the coach sees that there’s the opportunity for him, then getting these Test matches a year and half out from the World Cup is essential.”
Cheika also supported Rennie’s selection of Suliasi Vunivalu despite the former NRL star having another Super Rugby season blighted by injury.
“The guy’s obviously an X-factor player,” Cheika said.
“In the big Test matches those players who can create something out of nothing are the guys who can win you a game on one play.
“Vunivalu is that guy. He hasn’t had a lot of continuity around playing with some injuries but I think it’s a worthwhile punt by the coach.”
Rennie told reporters on Monday that he hadn’t bothered to watch England’s loss to the Barbarians at Twickenham.
He felt that game would have next to no bearing on the tour proper but was keenly awaiting Eddie Jones picking his final squad.
Rennie had, however, watched Leicester’s victory over Saracens in a thrilling Premiership final on Sunday.
He described the game as a “kick-fest” that could be a pointer to what the Wallabies could expect from England Down Under.
Rennie’s main injury concern was Taniela Tupou’s return from a significant calf injury but remained hopeful that his star prop would be fit for the series opener in Perth on July 2.
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